Gas igniter

ABSTRACT

Disclosed is a gas igniter for gas heated grills wherein gas is sucked from the grill into an ignition chamber by increasing the volume of a contractable chamber. The ignited gas is blown out of the chamber by decreasing the volume of the contractable chamber.

United States Patent In ventor Linus K. Ihhn I920 Hillside Drive. Columbus, Ohio 3221 Appl No. 835,373 Filed In 23, I969 Patented July I3, 1971 GAS IGNITER 16 Claims, 14 Drawing I'Ip.

[1.8. CI 126/41, 431/6, 431/191. 431/263. 431/274 Int. Cl ..I"23q 21/00, F 24c 3/10 Field olSem-ch 126/25 B.

ReIerences Cited UNITED STATES PATENTS 7/1947 Simmons. 431/263 X 9/1958 Kunzler..... 431/263 X 1/1967 Harvey i. 126/25 B 8/1969 Branson 126/39 FOREIGN PATENTS 10/1954 Germany 431/263 Primary Examiner-Charles J Myhre Attorney- Lowe and King ABSTRACT: Disclosed is a gas igniter for gas heated grills wherein gas is sucked from the grill into an ignition chamber by increasing the volume ofa contractable chamber. The ignited gas is blown out of the chamber by decreasing the volume of the contractable chamber.

GAS IGNITER The present invention relates generally to gas igniters and, more particularly, to a gas igniter wherein gas is sucked from a grill into an ignition chamber and the ignited gas flows back to the gas source.

Grills for cooking food in outdoor environments have recently received widespread use. These grills or furnaces are characterized by a burner unit having a multiplicity of apertures through which combustible gas under pressure, usually from a natural gas source, is forced. Typically, the burner is covered by a grating carrying a multiplicity of ceramic bricks, over which a grid is placed for carrying food to be cooked.

To avoid some of the dangers inherent with igniting a grill of this type with a match, an igniter has been developed utilizing a spark gap placed in proximity with the gas burner apertures. In one typical model, the spark gap for igniting the gas comprises a piezoelectric crystal which generates a high voltage in response to mechanical squeezing thereof. The high voltage is developed across the spark gap in close proximity to the gas burner apertures and causes spontaneous ignition of the gas in proximity thereto. The spark gap, being in close proximity with the gas burner apertures, is exposed to grease and dust particles from the food being cooked, as well as from other atmospheric contaminants. As grease and dust particles accumulate in the region of the spark gap and humidity varies in response to changing atmospheric conditions, it frequently develops that there is insufficient voltage to generate therspark for gas ignition. To maintain the conditions necessary for ignition with the prior art device, it is necessary to clean and maintain the spark gap periodically. Cleaning and maintenance of the spark gap can be achieved, however, only by removing the food grid and ceramic bricks, as well as the grid holding the bricks. In addition, it is occasionally necessary to disassemble the burner merely to gain access to the fixedly positioned spark gap.

In accordance with the present invention, these problems associated with prior art igniters for outdoor-type grills are obviated by providing a completely enclosed spark gap igniter for gas emerging from the burner apertures and locating the igniter at a region remote from the apertures. By enclosing the gas ignition spark gap chamber, grease and dust are not collected in the vicinity of the spark gap. The spark gap is enclosed and removed from the region immediately adjacent the gas burner apertures by providing means, in the form of an expansible chamber, for sucking gas from the burner apertures into the ignition chamber. After the gas has been sucked into the chamber, it is ignited and the ignited gas propagates as a wave front back to the burner apertures to cause complete ignition of gas in the burner.

As a feature of the invention, the ignited gas is positively forced out of, i.e., exhausted from, the ignition chamber after combustion has taken place. The ignited gas is forced out of the chamber by activating the sucking means so that it is operated in a reverse mode, so that the volume of the expansible chamber is reduced to exert a pressure against the ignited gas by air that has previously been sucked through the ignition chamber. By forcing the ignited gas out of the combustion chamber immediately after ignition has taken place, the possibility of tire is obviated and excessive heating of the igniter components is not likely to occur. Thereby, the unit is inherently provided with a safety feature and long life.

It is, accordingly, an object of the present invention to provide a new and improved gas igniter.

Another object of the invention is to provide a new and improved gas igniter particularly adapted for use with gas grills of the outdoor type wherein problems associated with accumulation of grease and dirt in the ignition area are obviated.

An additional object of the present invention is to provide a gas burner igniter wherein gas is sucked from the burner into a combustion chamber.

Still another object of the invention is to provide a new and improved gas igniter, particularly adapted for use with burners for cooking food, wherein ignited gas in a combustion chamber is forcibly blown therefrom to enhance the safety characteristics and long life of the combustcr.

The above and still further objects, features and advantages of the present invention will become apparent upon consideration of the following detailed description of several specific embodiments thereof, especially when taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a perspective view, with a section partly broken away, of a typical grill of the prior art type, in combination with an igniter in accordance with the present invention;

FIGS. 2 and 3 are respectively top and side views illustrating the outlet end of the igniter of the present invention in combination with a typical prior art burner, with FIG. 3 being taken through the line 3-3 of FIG. 2;

FIG. 4 is a schematic view of the igniter of the present invention;

FIGS. 5 and 6 are respectively top and side sectional views of an igniter in accordance with an embodiment of the present invention utilizing a bellows as an expansible chamber, wherein FIGS. 5 and 6 show the bellows in expanded and contracted conditions, respectively, and FIG. 6 is taken along the line 6-6 of FIG. 5;

FIG. 7 is a side sectional view, taken along the line 7-7, FIG. 5, of the electrical mechanism for generating a voltage to produce a spark in the ignition chamber of the igniter illustrated by FIGS. 4-6;

FIG. 8 is a side sectional view, taken along the line 8-8, FIG. 5, of the ignition chamber;

FIG. 9 is a side sectional view of a modified expansible chamber for sucking gas from a burner into an ignition chamber and blowing the ignited gas back to the burner;

FIG. 10 is a side view of modified igniter wherein a flint and spark wheel are utilized to generate a spark;

FIG. 11 is a plan view, partly broken away, of still another embodiment of the present invention utilizing a single bellows;

FIG, 12 is a side sectional view of the embodiment of FIG. 11, taken through the lines 12-12 of FIG. 11;

FIG. 13 is a sectional view of a portion of the activator of the embodiment of FIG. 11, taken through the lines 13-13 of FIG. 12; and

FIG. 14 is a perspective view of the portion of the activator illustrated in FIG. ll.

Reference is now made to FIGS. 1-8 wherein there is illustrated a preferred embodiment of the present invention in combination with a grill 1! for heating or cooking food. The grill 1], FIG. I, typically includes a standard 12 on which is mounted a housing 13 having an elongated gas burner 14 with a multiplicity of gas outlet apertures 15 around the periphery thereof. Combustible gas is supplied to burner 14 through a conduit, not shown, which extends through standard 12 from a suitable pipeline or bottled natural gas source. Mounted directly above burner 14 is grating 17 upon which ceramic bricks 18 are placed for enabling food positioned on grid 19 to have a charcoal appearance and taste.

To enable gas fed into burner 14 to be combusted as it emerges from burner apertures 15, gas igniter, mounted in metallic housing 21, is fixedly mounted by suitable means on one side ofthe housing for grill 1]. Extending from housing 21 into the interior of the housing for grill 1] and into proximity with apertures 15 of burner I4 is gas line 24, having a diameter, position and connections to enable gas from the burner to be drawn into the igniter combustion chamber 27 through inlet port 33 of the chamber. A portion of pipe 24 extending through the grill housing has a threaded collar 23 on which nut 22 is threaded to hold the pipe in situ. Pipe 24 has an open end 25 flared both vertically and horizontally so that a relatively large volume. sufficient for ignition, of the combustible gas can be drawn from a substantial number of burner apertures 15 at the rounded edge of burner 14 that is in proximity with the open pipe end. The open end 25 of pipe 24 extends in close enough proximity to apertures 15 and beneath the upper flange 26 of burner M to substantially prevent grease and dust from reaching the mouth and interior of the pipe. Typically, the interior diameter of pipe 24, beyond the flared end 25, is on the order of one-eighth inch to control the amount of air normally entrained therein to only a quantity sufficient for lgnition within chamber 27,

To remove some of the ambient air from within pipe 24 and ignition chamber 27 and and thereby more readily enable gas from burner apertures 15 to be sucked into the ignition chamber, housing 21 is provided with an expansible chamber in the form of a pair of sealed bellows 28 and 29. Bellows 28 and 29 are preferably fabricated from a plastic coated material to provide the desired air seal, To enable bellows 28 and 29 to be easily expanded and prevent the buildup of back pressure within housing 21, the igniter housing is provided with apertures 30 so that the interior thereof is at atmospheric pressure.

The interiors of bellows 28 and 29 are connected via lines 3t and 32 to opposed walls of ignition chamber 27, having an inlet port 33 communicating with line 24 to enable gas to be drawn into the ignition chamber. The outside walls of baffles 28 and 29 are fixedly mounted to opposite plates 34 held in situ within the igniter interior by screws 35. The inside free walls of baffles 28 and 29, facing the interior of housing 2|, are secured to plates 36 so as to be driven by elongated cam 47 and compression springs 44 on screws 35. Cam 47 is rotated from the horizontally disposed position illustrated in FIG. to the vertically extending position of FIG, 6 by manually rotating handle 49 in the clockwise direction to turn shaft 48. The handle 49, shaft 48 and cam 47 are fixedly secured to each other and biased by coil spring 50, coaxial with the shaft, so that the cam is normally horizontally disposed and baffles 28 and 29 are compressed. In response to rotation of handle 49 and shaft 48 to a stop for the handle, cam 47 is rotated 90 to the vertical position illustrated by FIG. 6, whereby the free ends of baffles 28 and 29 are simultaneously pushed together towards the center of igniter housing 21 by springs 44. In response to handle 49 being released, the free ends of baffles 28 and 29 are at the same time forced towards the outside faces of the igniter housing by the bias of spring 50. In response to expansion of baffles 28 and 29, ambient air is drawn from line 24 and sucked past ignition chamber 27 into the expanded baffles. As air is drawn from line 24, gas flowing out of burner apertures is sucked into the interior of the gas line and ignition chamber 27. The volume of bellows 28 and 29 and of pipes 31 and 32 is such that there is sufficient air in lines 31 and 32 to prevent a substantial amount of gas from reaching the interior of the bellows to preclude substantially the possibility of gas ignition in the bellows.

With the bellows 28 and 29 almost in the fully expanded condition so that a substantial quantity ofgas has been sucked into ignition chamber 27, the gas in the chamber is ignited. To this end, ignition chamber 27 includes a grounded electrode 37 which forms a spark gap with electrode 38 to which a transient high voltage pulse can be applied, preferably by piezoelectric means operated in proper time sequence with opening of bellows 28 ans 29 to the desired extent. In response to the transient high voltage pulse being derived between electrodes 37 and 38, gas in ignition chamber 27 is ignited to produce an ignited gas wave front which travels along line 24 to gas burner apertures 15 in proximity with the flared end of line 24.

To assure positively the propagation of the ignited gas from ignition chamber 27 back to the mouth 25 of line 24, and prevent burning within chamber 27 for a substantial time interval, baffles 28 and 29 are compressed after the gas in chamber 27 has been ignited. Baffles 28 and 29 are compressed in response to release of handle 49 which occurs immediately after an operator rotates it to the stop. In response to release of handle 49 air is pushed out of the interior of baffles 28 and 29 as they are compressed and passes through lines 3] and 32 and ignition chamber 27 to force the ignited gas in the ignition chamber through pipe 24 into proximity with the burner aperture I5 proximate the flared mouth 25.

To achieve gas ignition within chamber 27 and form a spark between electrodes 37 and 38 as baffles 28 and 29 are being forced to and retracted from their full open position, a piezoelectric high voltage source is provided. The piezoelectric generator comprises a cylinder 53 of certain bimetal piezoelectric crystals, such as telluride, embedded in a porcelain housing 54. The upper surface of cylinder 53 is positioned to contact a circular metal wheel 55, eccentrically mounted on shaft 48, so that the crystal is variably compressed depending upon the angular position of handle 49, Electrode 57 of crystal 53 is connected through insulated wire 58 to electrode 38 within ignition chamber 27, while the bottom surface I50 of the crystal forms an electrode that is grounded by virtue of its electrical and mechanical connection metallic housing 21, as illustrated in FIG. 7. Thereby, the low voltage electrode 50 of crystal 53 and ignition electrode 37 are always at the same potential, and a DC connection exists between the crystal high voltage electrode 58 and high voltage ignition electrode 38.

In response to handle 49 and shaft 48 being rotated from their initial position to the stop position, crystal 53 is squeezed sufficiently by wheel 55 to enable a high voltage, sufficient for ignition of the gas in chamber 27, to be developed between electrodes 37 and 38. In response to the handle 49 being released and rotation of shaft 48 back towards its initial position, the crystal again generates a large enough voltage for gas ignition. Hence, two sparks in close time sequence are generated between electrodes 37 and 38 for each rotation of handle 49 to assure positive ignition of the gas in the cham ber. In operation, sufficient voltage for gas ignition is generated by crystal 53 across the spark gap in chamber 27 as bellows 28 and 29 are almost fully extended as handle 49 is rotated to approximately 5 of its stopv A similar voltage is generated in chamber 27 after handle 49 has been released and the bellows begin contracting.

In accordance with a modification of the invention, thus trated by FIG, 10, the electrical ignition arrangement specifically illustrated by FIGS. 4-8 can be replaced with a mechanical igniter of the grinding wheel, flint-type, such as employed in a cigarette lighter. In the embodiment of FIG. l0, ignition chamber 60 is mounted coaxially with shaft 48 and includes a flint 6i and grinding wheel 62 which is driven by shaft 48 and handle 49 through a four-to-one gear train 63 and slip clutch 64. The slip clutch 64 is connected with shaft 48 in such a manner as to prevent turning ofgrinding wheel 62 until handle 49 has been rotated to within IO of its stop. In response to handle 49 being rotated to within 10 of its stop, slip clutch 64 is engaged to rotate grinding wheel 62 through an angle 0M0 for the last 10 oftravel for the handle. It has been found that a 40 turn of grinding wheel 62 is sufficient usually to cause a spark to be generated between the grinding wheel and flint 61 to promote ignition of the gas within chamber 27. In response to handle 49 being rotated back to its initial, starting position, a further spark is generated so that if the first one does not cause combustion, there is likelihood of combustion being derived from the second spark. In the drawing, FIG. 10 shows only the igniter mechanism and cam 47, without a disclosure of baffles 28 and 29. It is to be understood, however, that the baffles are included and are mounted on screws 35 in the manner illustrated by FIGS. 5 and 6 and connected via lines 31 and 32 to exhaust ports 65 in chamber 60.

In accordance with another embodiment of the invention, the baffle arrangement of FIGS. 4-6 can be replaced with a suction device having a collapsible movable wall segment, as illustrated by FIG. 9. In the embodiment of FIG. 9, an annular airtight tube 71 having a flexible or collapsible inner wall 72 is provided. Tube 71 includes an inlet port 74 coupled via line 73 to an exhaust port in chamber 27 (similarly to the connection of one of lines 3| or 32 to chamber 27) and a relief port 75. Relief port 75 is normally closed by wheel 76 engaging inner wall 72 to force the inner wall against the outer wall of tube 71 so that the relief port communicates with ambient air outside the interior ofigniter 21 to prevent back pressure buildup. Wheel 76 is driven in a clockwise direction by shaft 48 with which it is connected by radial arm 77. There is thus provided a variable volume expansible chamber since the wheel squeezes a different section of flexible wall 72 against a portion of tube 71, depending upon the angular position of rod 77. With handle 49 in its normal initial position, wheel 76 is located in the position illustrated in FIG. 9 to provide a relatively large volume within tube 71 for air in pipe 24, ignition chamber 27 and port 33 of the ignition chamber. In response to rotation of handle 49 in a clockwise direction from its start position, wheel 76 is rotated in a clockwise direction, as illustrated in FIG. 9, to suddenly decrease the volume of tube 7I between inlet port 74 and the wheel without changing the amount of air in lines 24 or 73, as well as chamber 27. As wheel 76 is rotated further in the clockwise direction. the volume of tube 7] communicating with chamber 27 is increased but the amount of air in lines 24 and 73 and chamber 27 remains substantially constant. By increasing the volume within tube 7] for the air in lines 24 and 73 and chamber 27, air is sucked from the lines and ignition chamber 27 into the interior of the tube and the volume vacated by the sucked air is filled with gas from burner 15.

In response to wheel 76 being rotated a predetermined amount, gas within chamber 27 is ignited in accordance with either of the two previously discussed embodiments in response to handle 49 being rotated to a stop therefor. After the stop has been reached, handle 49 is released to rotate in the clockwise direction. back to its start position, and air within tube 7] is forced back out of port 74 through ignition chamber 27 and line 24, causing the ignited gas within the ignition chamber to flow back to burner apertures in proximity with the mouth 25 of pipe 24.

Reference is now made to FIGS. I l-I4 wherein there is il- Iustrated still another embodiment of the present invention utilizing a single bellows and a spark wheel. In the embodiment of FIGS. I 1-14, shaft 48 carries a generally radially ex tending, slightly flexible plastic arm 81. One end of arm 81 is fixedly secured to shaft 48 so that the arm is rotatable with the shaft. At the end of arm 8I remote from its connection with shaft 48 is mounted bellows assembly 82. Bellows assembly 82 includes an expansible section 83, having one exposed face rigidly connected to plate 84, fixedly mounted on the interior of igniter housing 21. The other exposed face of bellows 83 is provided with a hook 85, which extends from the end plate of the bellows and in a direction transversely of the bellows expansion direction, leaving adequate room for arm 81 to be inserted between the hook and the end face of the bellows.

The connection of arm 8] with bellows assembly 82 enables the bellows to be drawn from the closed position, illustrated in FIG. ll, to the open position indicated by dotted lines 86. With the bellows assembly 83 expanded, to the position indicated by dotted lines 86, hook 85 is rotated from a position in proximity to plate 84 to a position adjacent stop plate 87, proximate the wall of housing 21 opposite from that carrying plate 84. Air is sucked into bellows 83 by virtue of the connection of pipe 88 through an aperture in plate 84 to the interior of bellows assembly 82. Pipe 88 provides a gas flow path from the interior of bellows 83 through spark chamber 89, passage 33 and line 24 (not illustrated in FIGS. 11-14) to apertures IS in burner )4.

Spark chamber 89 includes spark wheel 91 and flint 92 which is biased against the spark wheel by spring 93. One end of spark wheel 91 is mounted for rotation about an axis longitudinal with passageway 33 by virtue of a rigid connection between the spark wheel and shaft 94, mounted for rotation in bearing I95, carried by spider 96 in passageway 33. Spark wheel 9] is rotatably connected to shaft 48 through a one-way clutch comprising ratchet wheel 95, pawl 96 and torsion spring 97 which is connected between the pawl and shaft 48.

The ratchet, pawl and torsion spring connection between spark wheel 9] and shaft 48 is such that the spark wheel is rotated on an impulse basis by an amount sufficient to produce a spark in chamber 89 only after handle 49 has been rotated to open bellows assembly 82 completely. To this end, shaft 48 is provided with a longitudinal slot 98 in one end thereof. Within slot 98 and oriented thereto, a further slot 99 for receiving one end of torsion spring 97 is provided. Torsion spring 97 is fixedly mounted in slot 99 at one end, while the other end of the torsion spring is fixedly attached to shaft 10I, rigidly mounted on wheel 102 for carrying pawl 96. Slot 98 is cut in shaft 48 in such a manner as to enable rotation of the shaft 40 before both edges of torsion spring 97 come into contact with opposed slot edges. Thereby, a dead band of approximately 40 is provided between the rotation of shaft 48 and spark wheel 91 but the spark wheel is driven with a sudden turn of approximately 25 after the dead band region has been overcome. The 25 rotation of spark wheel 91 is sufficient usually to provide ignition from gases sucked into chamber 89.

In operation, an operator rotates handle 49 approximately 40 from the vertically extending position illustrated in FIG. I2 so that bellows assembly 82 is opened to the position indicated by dotted line 86, FIG. I]. As bellows 83 are opened, air in the line from the flared end 25 of pipe 24 is sucked into the bellows and gas from apertures I5 is sucked into combustion chamber 89. With handle 49 rotated about 40 to its fullest extent, shaft 48 is turned so that the opposite edges of torsion spring 97 are in contact with the opposed surfaces 103 and 104 forming the sidewalls of slot 98. Prior to the opposite edges ofspring 97 engaging walls 103 and 104, spark wheel 91 is held stationary due to the frictional force exerted thereon by spring biased flint 92. In response to walls 103 and I04 coming into contact with the opposite edges of torsion spring 97, however, the energy stored in the torsion spring is released and suddenly imparted to spark wheel 91 through shaft 101, wheel I02, pawl 96 and ratchet wheel 95. Shaft 48 provides an added torque to the spark wheel assembly after bellows assembly 82 has become fully extended because bellows expander arm 81 has sufficient flexibility to function as a leaf spring and thereby enable it to slide slightly out of bellows hook 85, as shown by dotted line position 90, FIG. I].

In response to the sudden application of force applied thereto, spark wheel 91 is suddenly rotated approximately 25 to produce a spark in chamber 89 and cause ignition of the natural gas sucked therein. The ignited has in chamber 89 flows back through bore 33 and pipe 24 to apertures 15 to ignite the gas escaping from the apertures. Simultaneously, the operator releases handle 49 and the handle returns to its initial vertical position due to the bias of return spring 50. As handle 49 and shaft 48 return to their initial position, the air in bellows assembly 82 is forced through pipe 88 and chamber 89 positively to push the ignited gas in the ignition chamber back into proximity with apertures l5 and ignite the burner.

As gas is being forced out of chamber 89 in response to contraction of bellows 83, spark wheel 91 remains stationary despite its connection to shaft 48 because of the inclusion of the one-way clutch comprising ratchet wheel and pawl 96. Thereby, the spark wheel 91 is activated only once for each rotation of handle 49 to reduce wear to flint 92 and extend the flint life.

While there have been described and illustrated several specific embodiments of the invention, it will be clear that variations of the details of construction which are specifically illustrated and described may bemade without departing from the true spirit and scope of the invention. For example, to further obviate the possibility of grease and other debris reaching the interior of pipe 24, the pipe can be extensible into and out of proximity with burner apertures 15. Further, other means for igniting the gas can be employed, such as a magneto geared with shaft 48 for generating a DC voltage to heat a resistive ignition wick within chamber 27. Further, the sucking bellows and tube can be replaced with an impeller geared with shaft 48.

I claim:

1. An igniter for combustible gas emerging from a gas burner comprising an ignition chamber for the gas, gas line means having one end in proximity to the gas emerging from the burner and a second end terminating in said chamber, means for drawing the emerging gas from the burner through the line into the chamber, and means operated in a predeter mined time sequence with said drawing means for igniting gas drawn into the chamber, said line means being coupled with said chamber and burner for feeding ignited gas from the chamber back to the burner so that an ignited wave front propagates via the line means back to the burner to ignite gas emerging from the burner.

2. The igniter of claim I wherein said drawing means includes means for forcing the ignited gas out of the chamber after activation of the ignition means.

3. The igniter of claim 2 wherein said means for drawing further includes means for drawing ambient air out oithe gas line and chamber while drawing the gas through the gas line and chamber.

4. The igniter of claim 3 wherein said drawing means includes; an expansibie chamber, and means for expanding the volume of the expansible chamber to draw the gas into the ig nition chamber and for reducing the volume of the expansible chamber to force the ignited gas out ofthe ignition chamber.

5. The igniter oiclaim 4 wherein said ignition means inciudes means for generating a first spark within the ignition chamber after the expansible chamber is opened and for generating a second spark within the ignition chamber as the expansible chamber is being closed.

6. The igniter of claim 5 further including coaxial actuators for said igniter means and expansible chambers.

7. The igniter of claim 4 wherein said igniting means includes: a rotatable shaft, spark generating means in said ignition chamber, and dead band means between said shaft and spark generating means for enabling a spark to be generated by said spark generating means only in response to the shaft being rotated through a predetermined angle.

8. The ignite of claim 7 wherein said expanding means includes a flexible arm rotatable with said shaft, and said expansible chamber includes hook means for receiving said arm and enabling the arm to be partially retracted from it.

9. The igniter of claim 8 further including a one-way clutch between said shaft and spark generating means.

10. The igniter of claim 8 wherein said dead band means includes a slot in said shaft and a torsion spring having one end fixedly mounted in a root of said slot and another end fixedly mounted to a drive means for said spark generating means, said spring being rotatable in said slot by said predetermined angle.

ll. The igniter of claim 7 wherein said dead band means includes a slot in said shaft and a torsion spring having one end fixedly mounted in a root of said slot and another end fixedly mounted to a drive means for said spark generating means, said spring being rotatable in said slot by said predetermined angle.

12. The igniter of claim 1 wherein the one end of said gas line is outwardiy flared.

13. A grill for heating and cooking with combustible gas comprising a burner for the gas, said burner having apertures for enabling gas to be combusted in the atmosphere, means for mounting noncombustible heat-retaining bricks in proximity to said burner, means for supporting an object to be cooked in proximity to said mounting means, an ignition chamber for the gas, a gas line having one end in proximity to apertures of the gas burner and a second end terminating in said chamber, means for drawing gas escaping from the burner apertures through the line into the chamber, and means operated in predetermined time sequence with said drawing means for lg niting gas drawn into the chamber.

[4. The grill of claim 13 wherein said drawing means includes means for forcing the ignited gas out of the chamber after activation of the ignition means.

IS. The grill of claim 14 wherein said means for drawing further includes means for drawing ambient air out of the gas line and chamber while drawing the gas through the gas line and chamber.

l6. A method of igniting combustible gas emerging from a source comprising the steps ofsucking the gas from the source to an ignition chamber, igniting the gas in the chamber after it has been sucked into the chamber, and applying fluid pressure to the ignited gas in the chamber to force the ignited gas to flow out ofthe chamber back to the source. 

1. An igniter for combustible gas emerging from a gas burner comprising an ignition chamber for the gas, gas line means having one end in proximity to the gas emerging from the burner and a second end terminating in said chamber, means for drawing the emerging gas from the burner through the line into the chamber, and means operated in a predetermined time sequence with said drawing means for igniting gas drawn into the chamber, said line means being coupled with said chamber and burner for feeding ignited gas from the chamber back to the burner so that an ignited wave front propagates via the line means back to the burner to ignite gas emerging from the burner.
 2. The igniter of claim 1 wherein said drawing means includes means for forcing the ignited gas out of the chamber after activation of the ignition means.
 3. The igniter of claim 2 wherein said means for drawing further includes means for drawing ambient air out of the gas line and chamber while drawing the gas through the gas line and chamber.
 4. The igniter of claim 3 wherein said drawing means includes: an expansible chamber, and means for expanding the volume of the expansible chamber to draw the gas into the ignition chamber and for reducing the volume of the expansible chamber to force the ignited gas out of the ignition chamber.
 5. The igniter of claim 4 wherein said ignition means includes means for generating a first spark within the ignition chamber after the expansible chamber is opened and for generating a Second spark within the ignition chamber as the expansible chamber is being closed.
 6. The igniter of claim 5 further including coaxial actuators for said igniter means and expansible chambers.
 7. The igniter of claim 4 wherein said igniting means includes: a rotatable shaft, spark generating means in said ignition chamber, and dead band means between said shaft and spark generating means for enabling a spark to be generated by said spark generating means only in response to the shaft being rotated through a predetermined angle.
 8. The ignite of claim 7 wherein said expanding means includes a flexible arm rotatable with said shaft, and said expansible chamber includes hook means for receiving said arm and enabling the arm to be partially retracted from it.
 9. The igniter of claim 8 further including a one-way clutch between said shaft and spark generating means.
 10. The igniter of claim 8 wherein said dead band means includes a slot in said shaft and a torsion spring having one end fixedly mounted in a root of said slot and another end fixedly mounted to a drive means for said spark generating means, said spring being rotatable in said slot by said predetermined angle.
 11. The igniter of claim 7 wherein said dead band means includes a slot in said shaft and a torsion spring having one end fixedly mounted in a root of said slot and another end fixedly mounted to a drive means for said spark generating means, said spring being rotatable in said slot by said predetermined angle.
 12. The igniter of claim 1 wherein the one end of said gas line is outwardly flared.
 13. A grill for heating and cooking with combustible gas comprising a burner for the gas, said burner having apertures for enabling gas to be combusted in the atmosphere, means for mounting noncombustible heat-retaining bricks in proximity to said burner, means for supporting an object to be cooked in proximity to said mounting means, an ignition chamber for the gas, a gas line having one end in proximity to apertures of the gas burner and a second end terminating in said chamber, means for drawing gas escaping from the burner apertures through the line into the chamber, and means operated in predetermined time sequence with said drawing means for igniting gas drawn into the chamber.
 14. The grill of claim 13 wherein said drawing means includes means for forcing the ignited gas out of the chamber after activation of the ignition means.
 15. The grill of claim 14 wherein said means for drawing further includes means for drawing ambient air out of the gas line and chamber while drawing the gas through the gas line and chamber.
 16. A method of igniting combustible gas emerging from a source comprising the steps of sucking the gas from the source to an ignition chamber, igniting the gas in the chamber after it has been sucked into the chamber, and applying fluid pressure to the ignited gas in the chamber to force the ignited gas to flow out of the chamber back to the source. 